Pathogens Of Acute Respiratory Infections Research Articles

Epidemiological and pathological characterization of acute respiratory infections.

This research comprehensively investigates the epidemiological features and pathogen profile of acute respiratory infections (ARI) in Shihezi City, Xinjiang. A pivotal aspect of this study is the construction of a Bayes discriminant function for principal pathogen infections. This innovative methodology aims to furnish a robust scientific basis for the prevention and clinical management of ARI, potentially guiding more effective strategies in both public health and clinical settings. We compiled and examined data from January 2020 to June 2023, pertaining to patients admitted with acute respiratory infections at the First Affiliated Hospital of Shihezi University. This investigation focused on discerning patterns in epidemiology and pathogen etiology. Among 2110 cases of acute respiratory infections (ARI), 1736 underwent pathogenetic testing. Of these, 595 cases tested positive for at least one pathogen, marking a positivity rate of 34.27%. Viral detections, at a rate of 27.47%, were notably higher than bacterial detections, which stood at 6.51%. The most prevalent viruses identified were Human respiratory syncytial virus (hRSV), Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), and Human adenovirus (HAdV), while the dominant bacterial pathogens included Klebsiella pneumoniae, Haemophilus influenzae, and Staphylococcus aureus. Co-infections were observed in 76 cases, accounting for 12.77% of positive diagnoses, predominantly involving hRSV in conjunction with other pathogens. In cases of acute bronchiolitis, hRSV was the most frequent pathogen, contributing to 23.10% of such cases. Similarly, in severe pneumonia cases, SARS-CoV-2 was predominant, accounting for 25.4% of these infections. The group with bacterial positivity exhibited elevated levels of C-reactive protein (CRP, 19.17 mg/L) and neutrophilic granulocyte percentage (NE%, 54.7%). The Bayes discriminant function demonstrated an initial validation accuracy of 74.9% and a cross-validation accuracy of 63.7%. The study underscores that hRSV, SARS-CoV-2, and HAdV are the primary pathogens in acute respiratory infections in the Shihezi region. Pathogen susceptibility exhibits variation across different age groups, with a higher pathogen detection rate in children compared to adults. The Bayes discriminant function shows significant promise in the classification and diagnosis of major pathogenic infections.

Comparison of two multiplex PCR tests for common pathogen detection in hospitalized children with acute respiratory infection.

Multiplex PCR methods have significantly improved the diagnosis of acute respiratory tract infections (ARTIs) in children. The ResP-CE System coupled with capillary electrophoresis is a highly specialized, automated, and expensive technology for detecting common pathogens in ARTIs. The XYRes-MCA System, a remarkably less expensive multiplex PCR instrument, employs hybridization for the detection of ARTI pathogens. Both methods detect 9 common microorganisms in ARTIs, i.e., RSV, FLUAV, FLUBV, ADV, PIV, HMPV, HBOV, HCOV, and MP. In this study, we aimed to compare the performance of these two methods in the detection of pathogens from sputum specimens collected from children with ARTIs. Sputum specimens were collected from 237 hospitalized children with ARTIs. Nucleic acid was extracted on an automated workstation. The ResP-CE and XYres-MCA systems were applied to detect pathogens from the samples, and the test result agreement between the two methods was evaluated using Kappa statistics. The ResP-CE and XYres-MCA identified pathogens, single or in combination, in 151 (63.7%) and 171 (72.1%) of 237 samples, respectively. Approximately 85% of positive samples identified by either method contained a single pathogen. Moderate to almost perfect concordance between the two methods was found in detecting the following 7 pathogens: RSV, FLUAV, FLUBV, PIV, HMPV, HBOV, and MP. These two methods are comparable in detecting common pathogens of ARTIs in children. As XYres-MCA analysis is more cost-effective, it could play an important role in diagnosing ARTIs in children in less economically developed regions.

Pharynx infectious and inflammatory diseases local etiotropic therapy efficacy comprehensive assessment in preschool and primary school-age children

Background. The oropharyngeal microbiota is important in maintaining resistance, eliminating viruses and regulating local protective reactions in response to inflammation in acute respiratory infections.
 Aim. To evaluate of the effect of topical etiotropic therapy on clinical manifestations, elimination of viruses and on oropharyngeal microbiota in the treatment of acute infectious inflammation of the throat that occurred as part of acute respiratory infections in children aged 510 years.
 Materials and methods. 120 outpatient patients randomized into 3 equal groups were treated for 7 days: in Group 1 0.2% hexethidine-containing aerosol, in Group 2 0.03 mg combined spray gramicidin S and 0.1 mg cetylpyridinium chloride, in Group 3 0.01% topical solution containing benzyldimethyl-myristoylamino-propylammonium. Changes in the severity of clinical manifestations were compared (integral indicator modified Tonsillopharyngitis Severity Score TSSm for children, the severity of the "sore throat" symptom on the WongBaker scale, the severity of local signs of inflammation according to pharyngoscopy data) in groups at Visit 2 (day 51) and Visit 3 (day 121) compared with the Visit 1. The elimination of acute respiratory infection pathogens was evaluated: polymerase chain reaction (PCR) of oropharyngeal smears obtained on days 1, 3 and 5 (1) PCR-1, PCR-2, PCR-3 respectively, with the detection of 12 respiratory viruses, including SARS-CoV-2. The state of the microbiota was assessed by sequencing the full-size 16S gene in samples obtained before and after treatment 1st and 12th (1) days, and compared with 19 indicators in healthy.
 Results. By Visit 3, the decrease in TSSm indicators was: 4.01.07 in Group 1; 5.01.48 in Group 2 and 4.01.02 in Group 3. The intergroup differences between Group 2 and 1, Group 2 and 3 were statistically significant (p0.05). The severity of sore throat by Visit 3 decreased in groups 1, 2 and 3 respectively by 2.00.90, 2.50.61 and 2.10.60, intergroup differences between groups 2 and 1, 2 and 3 had statistical significance at p0.05. The time to achieve complete relief of the disease according to the TSSm indicator was (day, MSE): 16.61.47 in Group 1; 11.91.13 in Group 2 and 12.41.38 in Group 3, intergroup differences (groups 1 and 2) are significant, p0.05. The time of complete relief from sore throat for groups 13 was 12.60.96, 8.00.87 and 9.41.01 respectively, intergroup differences (groups 1 and 2) were significant, p0.05. By Visit 2, the proportion of patients with a negative PCR result increased in Group 1 by 25%, in Group 2 by 43% and in Group 3 by 38%, which corresponded to the elimination of 81, 92 and 74% of viruses detected in groups according to PCR-1 and PCR-2. The microbiota of participants in all groups before treatment differed from the microbiota of healthy in terms of alpha and beta diversity, as well as in terms of indicators obtained by the NearesBalance method. After completion of treatment, changes in the microbiota in terms of beta diversity were observed in all groups compared to the initial state. In contrast to groups 1 and 3, in Group 2 there were statistically significant changes in species-level balances between groups of microbes that distinguish between sick and healthy, towards indicators of healthy.
 Conclusion. Topical etiotropic medications provide rapid relief of complaints and local signs of inflammation in the treatment of patients aged 510 years with sore throat in acute respiratory infections and contribute to the rapid elimination of pathogens of acute respiratory infections. A combined preparation containing an antiseptic and a bacteriocin-like antimicrobial peptide gramicidin S provides a more pronounced therapeutic effect at an earlier time and the elimination of 90% of all respiratory viruses, including SARS-CoV-2, by the fifth day of therapy, and also has the most sparing effect on the oropharyngeal microbiota compared to antiseptic monopreparations, which may explain its more pronounced anti-inflammatory effect.

Contribution of the FilmArray BioFire® Technology in the Diagnosis of Viral Respiratory Infections during the COVID-19 Pandemic at Ibn Sina University Hospital Center in Rabat: Epidemiological Study about 503 Cases.

Respiratory viruses are the most involved pathogens in acute respiratory infections. During the COVID-19 pandemic, new elements have been brought to this topic, especially at the diagnostic and therapeutic level. The objective of this work is to describe the epidemiology of respiratory viruses in patients admitted to the Ibn Sina University Hospital of Rabat during a period characterized by the emergence and spread of SARS-CoV-2. We conducted a retrospective study from January 1 to December 31. We included all patients treated for acute respiratory infection and for whom a multiplex respiratory panel PCR was requested. Virus detection was performed using a FilmArray RP 2.1 plus BioFire multiplex respiratory panel. The study population was relatively adults with a mean age of 39 years. The sex ratio M/F was 1.20. The survey revealed a high prevalence of 42.3% of patients hospitalized in the adult intensive care unit whose respiratory distress was the most common reason for hospitalization (58%). The positivity rate was 48.1%. This rate was higher in the pediatric population 83.13% compared to adults 29.7%. Monoinfection was found in 36.4% of cases, and codetection in 11.7% of cases. This survey revealed that a total of 322 viruses were detected, HRV being the most incriminated virus (48.7%), followed by RSV in 13.8% of patients. Considering the five most detected viruses in our study (HRV, RSV, PIV3, ADV, and hMPV), we found that the incidence was significantly higher in the pediatric population. SARS-CoV-2 was detected only in adult's population. In our study, we found that influenza A and B viruses, PIV2, MERS, and all bacteria were not detected by this kit during the study period. Regarding the seasonal distribution, RSV and hMPV showed a significantly high incidence during autumn and summer and SARS-CoV-2 and CoV OC43 showed a high peak during winter. In this study, we found a lack of detection of influenza virus and a shift in the usual winter peak of RSV to the summer, while the detection of ADV and HRV was less affected. This difference in detection could be due on the one hand to the difference in stability between enveloped and nonenveloped viruses and on the other hand to the escape of certain viruses to the different sanitary measures introduced after the declaration of the COVID-19 pandemic. These same measures were effective against enveloped viruses such as RSV and influenza viruses. The emergence of SARS-CoV-2 has modified the epidemiology of other respiratory viruses, either directly by viral interference or indirectly by the preventive measures taken.

Experience in developing a new test system for screening and diagnosis of infections that cause acute respiratory diseases, and its use

Relevance. Acute respiratory infections (ARI) are a serious health problem not only because of the high frequency of their occurrence, but also because of the economic damage they cause both in the form of direct costs (the cost of diagnosis and treatment) and indirect costs (disability, reduced labor productivity, etc.). Pregnant women and children under 5 years of age are included in the group of patients with risk factors for complications of influenza and other ARI, therefore, an analysis of the etiological structure of ARI and influenza in obstetric hospitals is an urgent task. In recent years, there has been an urgent need to create a national complex diagnostic test system based on molecular genetic methods for detecting infectious agents that cause ARI. Aims. The aim of the study is to analyze the etiological structure of ARI and influenza in patients with clinical symptoms and to develop and implement a new test system for rapid screening and diagnosis of infections that cause ARI. Materials & methods. When studying the etiological structure of ARI and influenza, cultural studies of the nasal and pharyngeal mucosa were carried out, followed by identification of microorganisms using MALDI-TOF mass spectrometry and molecular genetic study (real-time PCR) using an experimental test panel containing primers that allow detecting the following viruses: influenza A, B viruses, parainfluenza viruses of the 1st, 2nd, 3rd and 4th types, coronaviruses OS43, HKU1, NL63, E229, respiratory syncytial virus, metapneumovirus, rhinovirus and adenovirus, as well as bacterial pathogens of ARI: Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus pyogenes, Moraxella catarrhalis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa. The test system was developed using the following methods: real-time PCR, a combination of reverse transcription and real-time PCR (RT-PCR) and the next generation sequencing (NGS) method. Results. The etiological structure of ARI and influenza was analyzed in patients with clinical manifestations (cough, tickling/sore throat/hyperemia of the mucous membrane of the palate and the back wall of the pharynx, shortness of breath/difficulty breathing, acute runny nose/nasal congestion). The species spectrum of bacterial and viral pathogens was revealed. A new test system based on PCR, real-time RT-PCR and NGS has been created for complex diagnostics of both viral and bacterial pathogens of ARI, consisting of three separate components: the main test system «ARI», which detects the main viral and bacterial pathogens of ARI, and two additional sets of reagents: «Oseltamivir resistance» and «Oseltamivir/ Zanamivir resistance». Conclusions. The new test system can be used to detect and differentiate nucleic acids of pathogens of ARI of humans. The test system seems to us promising for further use. As a result of the analysis of the etiological structure of acute respiratory infections and influenza, attention is drawn to a significantly smaller variety of identified pathogens in 2020 and a much more pronounced dominance of rhinovirus infection compared to our previous study in 2019.

Serotype Distribution and Characteristics of the Minimum Inhibitory Concentrations of Streptococcus pneumoniae Isolated from Pediatric Patients in Kunming, China

Streptococcus pneumoniae (S. pneumoniae) is the main conditional pathogen of acute respiratory infection in infants, children, and older adults worldwide. It was great significant to identify the epidemic characteristics of serotypes and antibiotic susceptibility for the prevention and treatment of S. pneumoniae diseases. This research assessed the serotype distribution and the minimum inhibitory concentrations (MICs) of S. pneumoniae isolated from pediatric patients to provide information on the epidemiology and antibiotic resistance of S. pneumoniae in Kunming, China. A total of 140 S. pneumoniae isolates were collected from pediatric patients at Kunming Children’s Hospital from January 2016 to October 2017. Serotype identification was done by Quellung reaction and multiplex polymerase chain reaction. MICs were determined by E-test. 140 isolates distributed in 13 types of serotypes. The top-three prevalent serotypes were 19F, 19A, and 6B. The immunization coverage rate of 13-valent pneumococcal conjugate vaccine (PCV) was relatively higher and should be introduced into the vaccination program in the region. MIC50 of penicillin, ceftriaxone, and levofloxacin was 1 μg/mL. MIC50 for meropenem and vancomycin was 0.38 μg/mL. MIC90 of penicillin, ceftriaxone, and levofloxacin was 1.5 μg/mL and that of meropenem and vancomycin was 0.5 μg/mL. The MIC90 of erythromycin was > 256 μg/mL. In summary, S. pneumoniae had low resistance rates to penicillin, ceftriaxone, levofloxacin, vancomycin, and meropenem, and these antibiotics could be the first-line agents for children with pneumococcal infections in Kunming.

Аргументы в пользу применения современных блокаторов H1-гистаминовых рецепторов для лечения больных с аллергическим ринитом, протекающим на фоне острой респираторной вирусной инфекции

Allergic rhinitis is characterized by a significant prevalence among the adult population. Patients with allergic diseases have a higher sensitivity to pathogens of acute respiratory infection of the upper respiratory tract (ARVI). Inflammation of the mucous membrane of the nasal cavity and paranasal sinuses in such patients is characterized by more pronounced symptoms and greater resistance to therapy. An observational study was conducted at the Department of Otorhinolaryngology of the Moscow State Medical University named after A. I. Evdokimov, during which the effect of modern antihistamines on the severity of nasal and non-nasal symptoms of inflammation was evaluated in patients who were diagnosed with the development of acute respiratory viral infections against the background of seasonal exacerbation of allergic rhinitis. The data of 50 patients divided into two groups were analyzed. In the first group (n = 25), benzhydrylpiperazinylbutylmethylxanthine succinate (Theoritin) was included in the therapy regimen, in the second – cetirizine preparations (n = 5). During the follow-up, each patient underwent a clinical assessment of the severity of nasal and non-nasal symptoms three times (1st, 7th and 14th days of follow-up), and the severity of nasal obstruction was assessed using anterior active rhinomanometry. According to the data obtained, there was a pronounced positive dynamics in both groups, while the clinical efficacy was confirmed by instrumental evaluation data. However, by the 7th day of treatment, the positive dynamics was more pronounced in the group of patients receiving theoritin as part of therapy. The use of modern antihistamines in patients comorbid for allergic rhinitis and acute respiratory diseases has a significant therapeutic effect. Theoritin provides more pronounced therapeutic effects in the early stages, which makes its further study and use of the drug for the treatment of acute respiratory viral infections against the background of allergic rhinitis promising.

Investigation of pathogenic agents causing acute respiratory tract infections in pediatric patients in a children's hospital assigned for case screening in Beijing during the outbreak of COVID-19

Objective: To investigate the spectrum of pathogenic agents in pediatric patients with acute respiratory infections (ARI) during the outbreak of coronavirus infectious diseases 2019 (COVID-19). Methods: Three groups of children were enrolled into the prospective study during January 20 to February 20, 2020 from Capital Institute of Pediatrics, including children in the exposed group with ARI and epidemiological history associated with COVID-19 from whom both pharyngeal and nasopharyngeal swabs were collected, children in the ARI group without COVID-19 associated epidemiological history and children in the screening group for hospital admission, with neither COVID-19 associated epidemiological history nor ARI. Only nasopharyngeal swabs were collected in the ARI group and screening group. Each group is expected to include at least 30 cases. All specimens were tested for 2019-nCoV nucleic acid by two diagnostic kits from different manufacturers. All nasopharyngeal swabs were tested for multiple respiratory pathogens, whilst the results from the ARI group were compared with that in the correspondence periods of 2019 and 2018 used by t or χ(2) test. Results: A total of 244 children were enrolled into three groups, including 139 males and 105 females, the age was (5±4) years. The test of 2019-nCoV nucleic acid were negative in all children, and high positive rates of pathogens were detected in exposed (69.4%, 25/36) and ARI (55.3%, 73/132) groups, with the highest positive rate for mycoplasma pneumoniae (MP) (19.4%, 7/36 and 17.4%, 23/132, respectively), followed by human metapneumovirus (hMPV) (16.7%, 6/36 and 9.8%, 13/132, respectively). The positive rate (11.8%, 9/76) of pathogens in the screening group was low. In the same period of 2019, the positive rate of pathogens was 83.7% (77/92), with the highest rates for respiratory syncytial virus (RSV) A (29.3%, 27/92), followed by influenza virus (Flu) A (H1N1) (19.6%, 18/92) and adenovirus (ADV) (14.1%, 13/92), which showed significant difference with the positive rates of the three viruses in 2020 (RSV A: χ(2)=27.346, P<0.01; FluA (H1N1): χ(2)=28.083, P<0.01; ADV: χ(2)=7.848, P=0.005) . In 2018, the positive rate of pathogens was 61.0% (50/82), with the highest rate for human bocavirus (HBoV) (13.4%, 11/82) and followed by ADV (11.0%, 9/82), and significant difference was shown in the positive rate of HBoV with that in 2020 (χ(2)=6.776, P=0.009). Conclusions: The infection rate of 2019-nCoV is low among children in Beijing with no family clustering or no close contact, even with epidemiological history. The spectrum of pathogens of ARI in children during the research period is quite different from that in the previous years when the viral infections were dominant. MP is the highest positively detected one among the main pathogens during the outbreak of COVID-19 in Beijing where there is no main outbreak area.

Antimicrobial activity of danofloxacin regarding to bacteria, pathogens of respiratory infections in pigs

The objective of the research was to study the antimicrobial activity of danofloxacin, the third-generation fluoroquinolone antibiotic, against bacteria, pathogens of acute respiratory infection in pigs. Samples of nasal excretions were selected from clinically sick weaned piglets with acute respiratory infection for microbiological investigation. The sensitivity test, carried out by the disc-diffusion method, showed a high level of the microflora sensitivity of the inflammatory exudate to danofloxacin. Bacteria Streptococcus suis and Bordetella bronchiseptica have been isolated and identified from biomaterial by generally accepted microbiological methods. The degree of antimicrobial activity of danofloxacin against isolated strains of microorganisms was established by determination the minimum inhibitory concentration (MIC) of danofloxacin for isolated bacteria by consecutive dilutions in a liquid nutrient medium. The MIC average of danofloxacin for Streptococcus suis isolates (n = 20) was 0.33 ± 0.082 μg/ml and for Bordetella bronchiseptica isolates (n = 8) – 0.21 ± 0.044 μg/ml. The obtained results showed a high level of bacteriostatic activity of danofloxacin regarding bacterial isolates, pathogens of acute respiratory infection in pigs. Danofloxacin, like other fluoroquinolones, is a critical antimicrobial substance for veterinary medicine. Therefore, chemotherapeutic agents based on this antibiotic can serve as a drug of choice for empirical treatment of pigs with acute respiratory infections of bacterial etiology. To right choose an effective agent for etiotropic therapy and minimize the selection of resistant strains of microorganisms, the antimicrobial susceptibility of isolated bacteria should be pre-established.

Etiologic and epidemiologic features of acute respiratory infections in adults from Shanghai, during 2015-2017

Objective: To analyze the etiologic and epidemiological characteristics of adult acute respiratory infections in Shanghai during 2015-2017. Methods: Data was collected from outpatients with acute respiratory infections who visited the Fever Clinics in three hospitals of different levels in three administrative regions of Shanghai, from 2015 to 2017. Basic information and nasopharyngeal swabs were collected from cases in line with the inclusion criteria. Multiplex RT-PCR and bacterial cultures were performed to detect the respiratory pathogens. Results: A total of 806 individuals were enrolled from 2015 to 2017. Respiratory pathogens were identified in 73.45% (592/806) of the cases, with the virus detection rate as 66.75% (538/806). It was found that the major respiratory pathogens for virus detection were influenza A in 326 (40.45%), influenza B in 116 (14.39%), rhinovirus/enterovirus in 39 (4.84%) of the cases. The overall detection rate of bacteria was 16.13% (130/806), including Klebsiella pneumoniae in 90 (11.17%) cases, Staphylococcus Aureus in 46 (5.71%) cases. Other kind of bacteria were not detected in our study. The detection rates on Mycoplasma pneumoniae was 5.33% (43/806) and on Chlamydia pneumonia was 0.37% (3/806). Co-infection with multiple pathogens was detected in 18.61% (150/806) of the cases, including 135 with double infection (accounting for 90.00%), 14 with triple infection and 1 with quadruple infection (accounted for 9.33% and 0.67%, respectively). Among the 150 cases with co-infections, the main identified pathogens were influenza A, Klebsiella pneumoniae, Staphylococcus aureus, and Mycoplasma pneumoniae. Pathogens of acute respiratory infections that identified among the outpatients from the Fever Clinics at different time, region or population, the characteristics were different (P<0.001). Conclusions: In 2015-2017, outpatients with acute respiratory infections in Shanghai were mainly caused by influenza virus or other viruses, however dynamically with its composition, time, region and characteristics of the population. It is necessary to strengthen and combine related medical and preventive services and to develop the appropriate strategies regarding clinical diagnosis and treatment.

Acute respiratory diseases: progression features, pharmaceutical therapy

Acute respiratory diseases (ARD) are widespread diseases and are of great social importance. Diagnosis of acute respiratory infections implies the damage to the respiratory system caused by a wide range of pathogens. Among the pathogens of acute respiratory infections are viruses of acute respiratory viral infection (ARVI) group, including influenza, as well as fungal and bacterial pathogens, which include intracellular bacteria: mycoplasma and chlamydia. Diseases caused by intracellular pathogens are treated by antibacterial drugs that can easily penetrate the cells and create there high concentrations.

A recombinant trivalent vaccine candidate against human adenovirus types 3, 7, and 55

Human adenoviruses types 3 (HAdV-3), 7 (HAdV-7) and 55 (HAdV-55) are major pathogens of acute respiratory infections (ARI) in children and adults. More than one type of HAdV can infect patients simultaneously, and the infections are sometimes fatal. However, there is currently no vaccine approved for general use in children and adults. Thus, development of a multivalent HAdV vaccine to combat HAdV infection becomes imperative. In this study, we constructed a new recombinant trivalent human adenovirus vaccine (rAdMHE3-h55), which expresses the hexon protein of HAdV-55 in the E3 region of rAdMHE3, a previously prepared bivalent vaccine candidate against HAdV-3 and HAdV-7. The results of in vitro neutralization assays indicate that rAdMHE3-h55 can induce the production of neutralizing antibodies against HAdV-3, HAdV-7, and HAdV-55 in mice. Furthermore, immunization with the recombinant trivalent vaccine candidate completely protected the mice challenged with HAdV-3, HAdV-7, orHAdV-55, respectively, showing lower lung viral loads and less lung Pathological changes was compared with those in unvaccinated mice. The current findings contribute to the development of a new adenovirus vaccine candidate and also advance this construction method for the generation of recombinant adenovirus vaccines. In conclusion, our recombinant trivalent vaccine rAdMHE3-h55 can provides protection against challenge with HAdV-3, HAdV-7, or HAdV-55 in mice. Future work of optimizing this vaccine candidate may lead to a more effective way of preventing respiratory diseases caused by common human adenoviruses.

Viral Infections in Egyptian Hospitalized Children with Acute Respiratory Tract Infections

Acute respiratory tract infections (ARTIs) are associated with significant morbidity and mortality worldwide, especially in developing countries. Children under the age of 5 years old are mostly affected. Both viral and bacterial causes are implicated, but viral etiologies are more difficult to diagnose. Viral infections can occur either single or mixed, but the significance and association of polyviral agents with the severity of cases are poorly understood. More studies are critical for understanding this role, improving diagnosis and treatment. Objective: To identify the rule of five chosen viral pathogens in ARTIs in children below 5 years old and the association of polyviral etiology with the severity of the disease. Methods: Nasopharyngeal swabs were taken from 120 children who had symptoms and signs of ARTIs, attending the outpatient clinic and admitted in pediatric department or pediatric intensive care unit, Banha university hospital. All children were subjected to full history taking, analysis by multiplex PCR for five viruses (Rhinovirus, Respiratory syncytial virus, Human metapneumovirus, Adenovirus, and Human boca virus). Results: 54 viruses were identified by multiplex PCR from 41 children (34.2%), 75.6% of them had a single viral infection, (17% and 7.4%) were co-infected with two and three viruses respectively. Positive cases were mostly of children admitted in pediatric ward and the majority were infants. URTIs was the most common presentation followed by bronchiolitis then bronchopneumonia. HRV was the most frequently detected as a single and mixed infection (35.2%) followed by RSV (22.2%). Non-significant correlation was found between mixed infection and the severity of infection. Conclusion: HRV is the most frequently recognized viral pathogen either as single or mixed in children below 5 years old in our patient group. Mixed infection has no correlation with disease severity. And using Multiplex PCR is an ideal tool for investigating mixed infection.

Prevalence and correlation of infectious agents in hospitalized children with acute respiratory tract infections in Central China.

Acute respiratory tract infections (ARTIs) are associated with significant morbidity and mortality worldwide, especially in children under the age of 5 years. Almost 2 million children die from ARTIs each year, and most of them are from developing countries. The prevalence and correlation of pathogens in ARTIs are poorly understood, but are critical for improving case prevention, treatment, and management. In this study, we investigated the prevalence and correlation of infectious agents in children with ARTIs. A total of 39,756 children with one or more symptoms, including fever, cough, sore throat, tonsillitis, pharyngitis, herpangina, pneumonia, and bronchiolitis, were enrolled in the study. All patients were hospitalized in Wuhan Children’s Hospital between October 1, 2010 and September 30, 2012, and were evaluated for infectious agents. Pathogens, including Mycoplasma pneumoniae, influenza A virus, influenza B virus, adenoviruses, respiratory syncytial virus, parainfluenza virus, Legionella pneumophila, Chlamydophila pneumoniae, and Coxiella burnetii, were screened simultaneously in patient blood samples using anti-pathogen IgM tests. Regression analysis was used to reveal correlations among the pathogens. Our results showed that one or more pathogens were identified in 10,206 patients, and that Mycoplasma pneumoniae, adenoviruses, and influenza B virus were the leading infectious agents. Mixed-infections of pathogens were detected in 2,391 cases, with Mycoplasma pneumoniae as the most frequent pathogen. The most common agents in the co-infections were Mycoplasma pneumoniae and influenza B virus. Regression analysis revealed a linear correlation between the proportion of mixed infections and the incidence of multi-pathogen infections. The prevalence of infectious agents in children with ARTIs was determined. Equations were established to estimate multiple infections by single-pathogen detection. This revealed a linear correlation for pathogens in children with ARTIs. This study provides useful information for improving case prevention and management.

Detection of viral and bacterial pathogens in acute respiratory infections

ObjectivesThe role of bacteria in acute respiratory illnesses (ARI) of adults and interactions with viral infections is incompletely understood. This study tested the hypothesis that bacterial co-infection during ARI adds to airway inflammation and illness severity. MethodsTwo groups of 97 specimens each were randomly selected from multiplex-PCR identified virus-positive and virus-negative nasal specimens obtained from adults with new onset ARI, and 40 control specimens were collected from healthy adults. All specimens were analyzed for Haemophilus influenzae(HI), Moraxella catarrhalis(MC) and Streptococcus pneumoniae(SP) by quantitative-PCR. General linear models tested for relationships between respiratory pathogens, biomarkers (nasal wash neutrophils and CXCL8), and ARI-severity. ResultsNasal specimens from adults with ARIs were more likely to contain bacteria (37% overall; HI = 28%, MC = 14%, SP = 7%) compared to specimens from healthy adults (5% overall; HI = 0%, MC = 2.5%, SP = 2.5%; p < 0.001). Among ARI specimens, bacteria were more likely to be detected among virus-negative specimens compared to virus-positive specimens (46% vs. 27%; p = 0.0046). The presence of bacteria was significantly associated with increased CXCL8 and neutrophils, but not increased symptoms. ConclusionPathogenic bacteria were more often detected in virus-negative ARI, and also associated with increased inflammatory biomarkers. These findings suggest the possibility that bacteria may augment virus-induced ARI and contribute to airway inflammation.

Etiology survey on virus of acute respiratory infection in Guangzhou from 2006 to 2009

To investigate the pathogens of acute respiratory infection (ARI) in Guangzhou from 2006 to 2009. A total of 1554 cases of ARI patients in Second Affiliated Hospital of Guangzhou Medical College from September 2006 to September 2009, were recruited in the survey. The sample of throat and pharyngeal swab were collected from each patient.11 types of virus including influenza A (FluA), influenza B (FluB), adenovirus (ADV), human rhinovirus (HRV), respiratory syncytial virus (RSV), parainfluenza virus type 1, type 2, type 3 (HPIV1, HPIV2, HPIV3), human metapneumovirus (MPV) and human coronavirus (HCoV) type 229E, type OC43 were detected by Fluorescence Quota PCR method. The epidemic feature and clinical characteristic of each virus were then analyzed. Virus were found in 1024 samples in total, accounting for 65.9% (1024/1554). RSV was the most common virus, which was found in 261 samples (16.8%); and followed by HRV as 13.9% (216/1554), FluA as 11.6% (181/1554), MPV as 6.5% (101/1554), FluB as 6.4% (99/1554), HPIV as 4.9% (76/1554), ADV as 3.5% (55/1554) and HCoV as 2.3% (35/1554). HPIV and HCoV shared a similar infection ratio among different age groups. The infection ratio of FluA and FluB was highest among 15-24 years old group, accounting for 16.5% (29/176) and 7.4% (13/176) respectively. MPV, RSV and HRV were the main pathogens caused infection among children under 4 years old, accounting for 9.7% (49/503), 21.7% (109/503) and 18.9% (95/503). The infection ratio of ADV was 6.0% (19/318), which was the most common pathogen among 5-14 years old patients. The incidence rate of HPIV and HRV showed no obvious seasonal features; while the prevalence of FluA, FluB, RSV, ADV, MPV and HCoV changed significantly in different seasons.22.2% (227/1024) ARI patients co-infected other respiratory virus.90.1% (163/181) FluA patients, 88.9% (88/99) FluB patients and 92.7% (51/55) ADV patients had high fever symptoms. RSV was the main pathogen of ARI, and the new-found virus MPV was also another crucial pathogen. Some pathogens' incidence rate were related to the season and patient's age. Co-infections of other respiratory virus were also detected in parts of ARI patients.

Frequency of Clamydia pneumoniae and Mycoplasma pneumoniae Infections in Children

Chlamydia pneumoniae and Mycoplasma pneumoniae are among the most important pathogens of acute respiratory infections in children between the ages of 5 and 15 years. We aimed to investigate seasonal frequency of respiratory infections caused by C. pneumoniae and M. pneumoniae, frequency of coinfection, clinical findings and to determine relationship between clinical findings and laboratory results. Total of 284 patients (ranging 5-15 years of age), admitted to out-patient clinic with symptoms of respiratory tract infections between January 2004 and June 2005, were enrolled in the study. IgA, IgG and IgM antibodies against C. pneumoniae were quantitatively detected in all serum samples by using microimmunofluorescence (MIF). For the M. pneumoniae infection an IgM titer in the ELISA test were analyzed. Nasopharyngeal smear samples were collected for PCR detection. Mean age was 8 +/- 2.2 (range 5-14) years. Mycoplasma pneumoniae IgM in 86 (30.2%) cases, C. pneumoniae IgM in one (0.3%) case, IgA in six (2.1%) cases and IgG in 10 (3.5%) cases were found positive. In 10 (3.5%) cases, both C. pneumoniae IgG (a titer of >1/216) and M. pneumoniae IgM were found positive concomitantly. The M. pneumoniae IgM in winter was found significantly higher compared to other seasons. Mycoplasma pneumoniae PCR method was performed on a total of 203 samples in 33 (16.2%) of which M. pneumoniae was found positive. The false positive ratio of PCR technique was found 16.2%. In a total of 217 examined samples by PCR method, the DNA of C. pneumoniae was found positive in two patients. Mycoplasma pneumoniae was a common pathogen in respiratory infections. The otherwise C. pneumoniae infections were rarely seen in children. A Comparison of serology diagnostic tests for M. pneumoniae infections was found more sensitive and specific than PCR.

Epidemiology of influenza virus infections in children with acute respiratory infections in Zambia.

A viral aetiological and epidemiological study of acute respiratory infections (ARI) in children was carried out in Lusaka, Zambia between June 1993 and September 1995. A total of 3,760 throat swab specimens were collected for virus isolation from children under 5 years of age who had ARI and were attending three health centres in Lusaka. Between June and November 1993, 52 cases of the influenza A/H3N2 viruses were isolated. Between May and July 1994, 34 influenza B cases were isolated. In 1995, one A/H3N2 influenza virus was isolated in January and then the same type of influenza virus was isolated from 55 samples between June and August. The isolation rate of influenza virus was highest at 14.3% (20/139) in August 1993, at 15.1% (18/119) in June 1994 and at 25.4% (43/169) in July 1995. This is the first report of a consecutive study of influenza virus infections in Zambia and the results reveal that influenza virus infections are one of the most important pathogens of ARI in children in the cool, dry season (June-August) in this country.